[MR relaxation time measurements with and without selective fat suppression (SPIR) in endocrine orbitopathy].
OBJECTIVE
To determine the value and utility of relaxation time measurements with magnetic resonance (MR) imaging in patients with Graves' ophthalmopathy (G.O.).


METHODS
20 orbits were studied in control subjects and 58 orbits in patients with G.O. T2 relaxation times of extraocular muscles and retrobulbar fat tissue were calculated. The thickness of the eye muscles was correlated with the calculated T2 times. 18 orbits were measured before and after retro-orbital radiation therapy.


RESULTS
Upper limits of determined normal T2 values were 60 ms in extraocular eye muscles and 40 ms in retrobulbar fat tissue. 89% (17/19) of the patients with G.O. had prolonged T2 times in extraocular eye muscles. The retrobulbar fat tissue in 5 of 38 orbits revealed minimal edema with the use of fat saturated sequences. T2 relaxation times decreased significantly (p < 10(-4)) after 10 Gy radiation therapy. No correlation was found between enlargement and T2 relaxation times in extraocular eye muscles (r = 0.44 in patients before radiation therapy).


CONCLUSIONS
In patients with G.O. the determination of the enlargement of extraocular eye muscles in computed tomography is not a sufficient parameter for an antiinflammatory therapy, since CT cannot visualise eye muscle edema. T2 relaxation time measurements with MR imaging allow differentiation between edematous and fibrotic changes. This is the diagnostic method of choice in patients with Graves' ophthalmopathy.
Pauleit
D
D
Radiologische Klinik, Universität Bonn.
Schüller
H
H
Textor
J
J
Leutner
C
C
Keller
E
E
Sommer
T
T
Träber
F
F
Block
W
W
Boldt
I
I
Schild
H
H
D000273:Adipose Tissue; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D004487:Edema / Q000000981:diagnostic imaging / Q000473:pathology; D005069:Evaluation Studies as Topic; D005260:Female; D005355:Fibrosis / Q000473:pathology; D005500:Follow-Up Studies; D006111:Graves Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000532:radiotherapy; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009801:Oculomotor Muscles / Q000000981:diagnostic imaging / Q000473:pathology; D009915:Orbit / Q000000981:diagnostic imaging / Q000473:pathology; D011879:Radiotherapy Dosage; D013997:Time Factors; D014057:Tomography, X-Ray Computed
MR-Relaxometriemessung mit und ohne frequenzselektive Fettunterdrückung (SPIR) bei endokriner Orbitopathie.